Backers of the HD-DVD format are planning to step up their promotional activities in North America, they said yesterday.

Toshiba, Intel, Microsoft, HP, Paramount, Warner and Universal Studios have established a company to raise awareness of HD-DVD. The format is one of two optical disc systems that is battling to become the de facto replacement for DVDs for high-definition content.

North American HD-DVD Promotional Group and its member companies are planning a $150m (about £81m) advertising campaign spanning the year-end holiday period and into 2007. The campaign will cover print, online, television and outdoor media and push both the format's hardware and movie titles due out over the coming months.

Toshiba began selling two HD-DVD players in North America in April, beating rival Blu-ray Disc to market by about two months. Speaking in late May a Toshiba executive said sales in North America were above 20,000. The first Blu-ray Disc player to go on sale was Samsung's BD-P1000, which hit stores in mid-June.